Boris Johnson today fleshed out his ambition to turn London into the electric car capital of Europe by promising that every Londoner would be within a one mile's reach of an electric car charging point within five years.

The mayor of London said today that electric cars were a way of reducing harmful emissions in the capital without settling for "hair-shirt abstinence".

But he made clear that he expected funding support from the government to turn his ambition for mainstream use of zero carbon electric vehicles into a reality.

The mayor is under pressure to find solutions to London's poor air quality – which is among the worst in Europe and risks incurring millions of pounds of EU fines for the UK government.

Johnson first announced in April his plans to introduce 100,000 cars to the capital's streets by building the charging point infrastructure to incentivise drivers to go electric.

In a speech at an event held today in Copenhagen for city mayors from around the world running parallel to the UN climate change summit, Johnson said that 25,000 charging points would be in place by 2015: 22,500 at workplaces, 500 on the streets of London and a further 2,000 in public car parks.

A one-stop website will be launched next year by Transport for London for electric vehicle drivers, with information on payment options and accessing the charging points across the capital expected the following year.

He also signalled a private-public membership scheme so that electric car users can register their vehicle in their borough.

Johnson told his fellow mayors that the "right conditions" needed to be in place to herald in a "golden era of clean, green electric motoring".

The mayor plans to lead by example by buying 1,000 electric vehicles for the Greater London authority fleet by 2015.

Johnson said: "There is an urgent need to tackle the risk of serious and irreversible climate change, yet this does not need to be about hair-shirt abstinence. I want to pursue radical yet practical steps to cut energy waste. Electric vehicles are a clear example of how technology can provide the solution to the biggest challenge of our generation."

The UK government faces the prospect of multimilillion-pound fines after the European commission announced on Friday it had rejected an application for an extension on meeting the EU limit values on dangerous airborne particles – known as PM10s – emitted by traffic, industry, and domestic heating, until 2011.

The government now has four months to resubmit before legal proceedings against the UK begin again, which could lead to millions of pounds of fines.

The Department of Environment, Food and Rural Affairs intends to send the Conservative mayor's draft air quality strategy, which was only published in October and includes the mayor's electric vehicle plans, as part of its new submission.

However, the mayor's draft strategy excludes two key elements that were included in the government's original submission to Europe to persuade the commissioner it could comply with the 2005 values by 2011: the western extension of the congestion charge, which the mayor intends to scrap, and the third phase of the low emission zone – which would penalise polluting vans – which Johnson has delayed until 2012.

Darren Johnson, a Green member of the London assembly, said despite the announcement "nothing significant would be delivered before 2012" in reducing emissions in the capital.

"Meanwhile, the mayor is taking several backward steps on climate change," he said.

"The scrapping of the £25 charge for gas guzzlers and the proposed abolition of the western extension of the congestion charge zone will reduce the cost of driving in London, while the mayor imposes massive increases in fares for public transport and drives people off the buses."

"The mayor's plan for electric vehicles in London will reduce air pollution, but do nothing to reduce road casualties, congestion or community disruption. He has failed to guarantee that all the charging points will be powered from renewable energy, which means that the short-term benefits to climate change are relatively small."